Note: Descriptions are shown in the official language in which they were submitted.
1;~35158
1 In the welding of one pipe section to another it
2 is conventional to encircle one section with a clamp pro-
3 voided with a plurality of jacks which extend beyond the
4 free end of the one pipe section and span the joint be-
tweet the two pipe sections that are to be welded together.
The jacks include jack screws which are adjustable radially
7 of the clamp so as to move into engagement with the second
8 pipe section and support one end of the latter in confront-
9 in relation with the free end of the pipe section on which
the clamp is mounted. The jack screws may be adjusted to
11 align the second pipe section with the first pipe section
12 and, in most cases, the jack screws may be adjusted so as
13 to reform or reshape the configuration of the second pipe
14 to match that of the first pipe. One wipe clamp construe-
lion of the kind described is disclosed in Dorymen U.S.
lo patent No. 3,653,574.
17 When preparing a clamp for use in aligning and no-
18 forming pipe sections the number of jacks that are required
19 may vary considerably. For example, a clamp of the kind
shown in the Dorymen patent has the advantage of being
21 usable with pipes of greatly differing diameters. Thus,
22 three circumferential spaced jacks may be adequate for
23 use with pipes of relatively small diameter, but it may
I be necessary to use six or more jacks with pipes of larger
diameter. Further, the number of jacks that may be no-
I squired is dependent, to a large extent, on the extent of
I reformation which may be required to conform the confront-
I in ends of the pipes. Thus, it may be necessary to pro-
vise more jacks for reforming than would be required for
simply aligning two pipe sections.
lZ3515~
1 When using a pipe clamp which is capable of accom-
2 modeling pipes of greatly differing diameters, it has been
3 the practice heretofore to fit the clamp with a number of
4 jacks and apply the clamp somewhat loosely to one of the
S pipe sections. Thereafter, the individual jacks may be ad-
jutted circumferential of the pipe to the approximate
7 positions they should occupy to enable the best results
8 to be obtained. It is not always possible to locate the
9 jacks initially as precisely as desired, so it often is
necessary to adjust the jacks' positions. This necessitates
11 loosening of the clamp and adjustment of the jacks, followed
12 by retightening of the clamp. This procedure sometimes
13 must be repeated several times before the jacks are post-
14 toned satisfactorily.
After a clamp has been fitted to one pipe section
I and the second pipe section is supported by the jacks in
17 axial alignment with the first pipe section, it often occurs
18 that there is a mismatch between the confronting surfaces
19 of the two pipe sections. This may be due to differences
in wall thicknesses or to an irregular bulge or indent-
21 lion in one pipe wall. This mismatch commonly is referred
22 to as a "hi-lo" condition, and such condition should be
corrected as much as possible prior to welding operations.
24 The best way in which to correct the hi-lo condition is
by a jack which can act on one or the other of the pipe
I sections so as to eliminate or minimize the mismatch. How-
27 ever, in clamps of the kind in existence heretofore, an
I additional jack could not be applied to the clamp without
loosening the latter. As a consequence, the alignment of
I
1;~35158
1 the two pipes necessarily would be lost as a result of
2 loosening of the clamp to enable it to accommodate another
3 jack. Thus, considerable time has been taken up heretofore
4 in aligning pipe sections and minimizing mismatches there-
5 between.
B When using a clamp which carries a number of jacks
7 that are intended to be spaced circumferential about a
8 pipe section when the clamp is applied, the combined weight
of the clamp and jacks may be more than can be handled con-
leniently by one, or even two, workers. The handling of
I heavy clamps is fatiguing and, if more than one person is
12 needed to apply a clamp to and remove it from a pipe sea-
13 lion, the welding costs are increased. Further, the heavier
14 the clamp the greater is the risk of injury to the person
lo or persons using such clamp.
I Accordingly, the present invention seeks to provide
17 a clamp construction which overcomes all of the problems
I referred to above.
19 The invention in its broader aspects pertains to a
Ed pipe clamp comprising a clamping member forming a
21 loop of such size as to encircle a first pipe adjacent one
22 end thereof with a plurality of supports being carried by
23 the clamping member and spaced circumferential of the
24 loop. A corresponding plurality of elongate body members
25 ¦ are carried by the respective supports and extend beyond
26 ¦ the loop a distance sufficient to project beyond the one end
27 ¦ of the first pipe and provide support for a second pipe in
28 ¦ confronting relation with the one end of the first pipe.
29 ¦ Adjustable force applying means is carried by each of the
30 ¦ body members for adjustment radially of the loop into and
31 ¦ out of engagement with the second pipe. Each of the supports
1;~35158
1 has a pair of relatively movable legs spaced apart a
2 distance sufficient to straddle the clamping member and
3 terminating at corresponding ends in grippers. Operating
4 means effect relative movement of the legs in directions
to cause the corresponding ends to move toward and away
from one another and enable the grippers to engage and
7 disengage the clamping member at opposite sides thereof.
More particularly, a clamp according to one
embodiment of the invention comprises a flexible chain
which snugly may encircle one pipe section adjacent
11 one end thereof and form a loop the size of which is
12 adjustable so as to enable the clamp to accommodate
13 a large number of different diameter pipe sections.
14 Any desired number of jacks may be applied to the
to chain at any desired location on the loop, and after
I the chain has been secured to the pipe. The jacks extend
17 beyond the end of the pipe to provide support for a second
18 pipe that is to be welded to the first pipe. The jacks
19 include jack screws that are adjustable radially of the
21
22
23
I
I
lZ3S158
1 clamp loop so as to shift the position of the second pipe
2 transversely of the first pipe and locate the end of the
3 second pipe in a predetermined position relative to the
4 first pipe.
If it appears that the second pipe requires reform-
in so that the configuration of its end will conform as
7 closely as possible to that of the adjacent end of the first
8 pipe, one or more additional jacks may be applied to the
9 clamp at selected locations so as to apply the necessary
lo force at the optimum positions.
11 If the radial adjustment of any one or more of the
12 jack screws necessitates relocation of a jack circumferen-
13 tidally of the clamp, it is a simple matter to release that
14 jack from the clamp and readjust its position as required.
lo According to another embodiment of the invention
I the jacks are the same as those referred to earlier, but
17 may be applied to a rim clamp composed of a pair of semi-
18 circular segments pivoted at corresponding ends so as to
19 encircle a pipe section. The other ends of the semi-circular
20 segments are equipped with a releasable latch mechanism so
21 as to enable the clamp to assume an annular configuration
22 having a diameter corresponding substantially to that of the
23 pipe. Again, the number and locations of jacks that may be
I applied to the clamp after it has been fitted to the pipe
25 is variable according to need.
a Apparatus constructed according to the invention
is described in the following specification and illustrated
as in the accompanying drawings, in which:
Figure 1 is a fragmentary, side elevation Al view
- 4
, ... .
~23~;~S~3
1 ¦ of a clamp chain applied to a pipe section;
2 ¦ Figure 2 is an end elevation, but illustrating
5 ¦ jack supports fitted to the chain;
4 Figure 3 is a sectional view taken on the line
3-3 of Figure 2 and illustrating a jack bar fitted to a
jack support;
7 Figure 4 is a sectional view similar to Figure 3,
8 but omitting the jack bar and illustrating how the jack
support is applied to and removed from the clamp chain;
Figure 5 is an elevation Al view of a modified form
11 of jack support;
12 Figure 6 is an end elevation of a pipe and a rim
15 clamp;
14 Figure 7 is an end elevation illustrating the rim
clamp applied to the pipe and also showing a number of
I jack supports fitted to the clamp;
17 Figure 8 is a fragmentary, side elevation Al view
18 illustrating a jack fitted to the rim clamp;
19 Figure 9 is a sectional view taken on the line
9-9 of Figure 8 and illustrating the manner of application
21 of the jack support to the rim clamp, the jack bar being
22 removed;
Figure 10 is a view similar to Figure 8, but thus-
I treating the jack support clamped to the rim clamp;
Figure 11 is an elevation Al view of a modified rim
I clamp, appearing with Figures 3, 4 & 5;
a Figure 12 is a view similar to Figure 11, but show-
I in the clamp in an adjusted position wow Figs. 3, 4 & 5; and
Figure 13 is a top plan view/ with Figs. 3, 4-& 5.
I
Jo _ 5
:~'
.
- issue
1 Apparatus constructed in accordance with each of
2 the embodiments hereinafter described is adapted for use in
3 welding a first pipe section 1 to a second pipe section 2,
4 the two pipe sections having confronting ends 3 and 4, no-
spectively, which may be beveled or otherwise suitably
6 shaped. Prior to welding the two pipe sections to one an-
7 other, they must be so located that their confronting ends
8 are in a predetermined location and are maintained in such
9 location until they are either tack or completely welded
to each other. Apparatus constructed in accordance with
11 the invention is especially adapted to perform these lung-
12 lions regardless of whether the second pipe section 2 is a
13 cylindrical or other configured pipe, a fitting, a valve,
14 or other device.
It The embodiment by the invention illustrated in
I Figures 1-4 comprises a clamp 5 composed of a roller chain
17 6 of predetermined length and formed of alternating groups
18 of links 7 and 8 pivotal joined by pins 9. Rollers 10
19 are interposed between adjacent links. At one end of the
chain is a block B having a V-shaped base 11 adapted to
21 seat upon the outer surface of the pipe section 1 and to
22 which is welded a pair of upstanding, spaced apart plates
23 12. Welded between the plates 12 is a hollow housing 13 in
I which is telescoping accommodated a tube 14 that is welded
at its outer end to one end of the chain 6. The sleeve 14
I has fixed to its inner end a threaded nut (not shown) through
which extends a correspondingly threaded shaft (not shown).
I The shaft also extends through a bearing 16 fitted onto the
I housing 13 and terminates at its outer end in an operating
I
lZ35158
1 ¦ crank 17 by means of which the shaft may be rotated so as
2 ¦ to effect extension or retraction of the sleeve 14 relative
3 ¦ to the housing 13.
4 ¦ The opposite end of the chain 6 is free and is
5 ¦ adapted to be threaded between the plates 12 and around a
6 ¦ mandrel 18 which spans the two plates 12. The chain also
7 ¦ passes between the mandrel 18 and a shaft 19 on which a
8 ¦ latch 20 is mounted for releasable, latching engagement
¦ with the chain 6. The arrangement is such that the chain
¦ 6 may form a loop L having a diameter corresponding to that
11 ¦ of the pipe 1, or any one of a number of other pipes of
12 ¦ either lesser or greater diameter. Once the loop L has
13 ¦ been formed around the pipe 1, the chain may be snugly
14 ¦ clamped in place on the pipe adjacent its free end 3 by
15 ¦ rotation ox the crank 17 in such direction as to tension
I ¦ the chair 6.
17 ¦ It is preferred that the block B include a jack
18 ¦ 21 comprising a bar 22 welded at one end to the adjacent
19 ¦ plate 12 and being of such length as to project beyond the
20 ¦ free end 3 of the pipe 1 when the-chain 6 is clamped thereon.
21 ¦ The jack 21 also preferably includes a pair of threaded
22 ¦ jack screws 23 and 24 extending through threaded openings
23 ¦ in the bar 22 for adjustment radially of the loop L. The
24 jack screw 23 has a swivel foot 25 for engagement with the
pipe section 1 and the jack screw 24 has a similar swivel
26 foot 26 for engagement with the pipe 2. Operating handles
I 27 and 28 may be fitted to the opposite ends of the screws
I 23 and 24, respectively, to facilitate their rotation.
Following clamping of the chain 6 onto the pipe
- 7
35158
1 section 1 a suitable number of jack supports 30 may be
2 applied to the chain circumferential of the loop L. Each
3 support 30 is identical and comprises a pair of legs 31
4 and 32 having aligned, elongate slots 33 and 34 for the
loose accommodation of a coupling bolt 35 having a head
36 at one end and an adjustable nut 37 at its other end.
r The legs 31 and 32 thus may be rocked about a fulcrum 38
8 formed by the bolt 35, and the maximum spacing between the
legs is adjustable by means of the nut 37 to enable the
support to be adaptable to chains of different widths.
11 it one end of the leg 31 is welded a gripper or
12 flange 39 and a similar gripper or flange 40 is welded to
13 the corresponding end of the leg 32. The grippers 39 and
14 40 have fingers 41 and 42, respectively, which extend be-
pond the associated leg toward each other. The free ends
I of the legs and the grippers preferably are concave but the
17 concavity need not match the curvature of the pipe.
18 Operating means for effecting rocking movements
19 of the legs about the fulcrum 38 is designated generally
by the reference character 43 and, in one embodiment, come
21 proses a shaft 44 rotatable accommodated in a sleeve 45
22 that is welded to the leg 31 adjacent one end thereof.
23 The sleeve 45 has a semi-circular slot (not shown) therein
24 through which extends one end of a threaded mounting member
47 that is fixed to the shaft 44. Threaded onto the rod
I 47 is an actuator 48 to which is fixed an enlarged head 49
I to facilitate rotation of the actuator 48. The leg 31 also
I is provided with a slot 50 adjacent the sleeve 45 and the
leg 32 is provided with a corresponding slot 51. The
I
1~35158
1 ¦ mounting member 47 thus may be accommodated in the slot 50,
2 ¦ as is shown in Figure 4, or in the slot 51, as is shown in
3 ¦ Figure 3. When the member 47 is accommodated in the slot
4 ¦ 51, rotation of the head 49 in such direction as to cause
5 ¦ the actuator 48 to move toward the leg 32 will result in
a ¦ rocking of the legs 31 and 32 about the fulcrum 38 in such
7 ¦ directions as to cause the grippers 39 and 40 to move toward
8 ¦ one another, and, as long as the actuator 48 is maintained
9 ¦ in engagement with the leg 32, the grippers 39 and 40 cannot
10 ¦ move away from each other. Locating the actuator 48 radially
11 ¦ outwardly of the fulcrum facilitates operation of the act
12 ¦ tutor.
15 ¦ The leg 31 has an opening 52 between its ends
14 ¦ and the leg 32 has a similar opening 53 in register with
15 ¦ the opening 52. The leg 31 also preferably has a nut 54
I ¦ welded thereto and through which extends a threaded set
17 ¦ screw 55.
18 ¦ Each support 30 is adapted to accommodate a jack
19 ¦ 56 comprising an elongate body 57 having spaced, parallel
20 ¦ side rails So, an end rail 59 at one end of the body, and
21 ¦ a threaded nut 60 fixed between the rails 58 at the oppo-
22 site end of the body. Extending through the nut 60 is a
23 correspondingly threaded jack screw 61 having a swivel foot
I 62 at one end and a head 63 and a handle 64 at its opposite
end to facilitate rotation. At the opposite end of the
I body 57 is a stabilizer bar 65 positioned between the rails
I 58 and pivoted thereto by means of a pin 66. The stabilizer
I bar 65 is lockable counterclockwise about the axis of the
pivot 66 from a retracted position substantially within
the confines of the body to an extended position as shown
~23~;8
1 in Figure 3. Further counterclockwise movement is pro-
2 eluded by engagement of the bar 65 with the end rail 59.
The cross-sectional area of the body 57 is slightly
4 less than the area of each of the openings 52 and 53 in the
legs of the support 30. Thus, the stabilizer bar 65 may be
rocked to its retracted position and the body 57 slid through
7 the openings in the legs 31 and 32, following which the
8 stabilizer bar 65 may be swung to its extended position.
9 The body 57 then may be adjusted longitudinally to a desired
position and the set screw 55 turned to engage the adjacent
11 rail 58 and latch the body in that position.
12 In the operation of the apparatus thus far de-
13 scribed, the chain 6 is clamped onto the pipe section 1 in
14 the manner described earlier. Thereafter, a number of
supports 30 may be fitted to the chain. In each case, the
I legs 31 end 32 will be rocked about their fulcrum 38 so as
17 to cause the grippers 39 and 40 to be spread apart a disk
18 lance sufficient to enable the legs 31 and 32 to straddle
19 the chain as is shown in Figure 4. The operating means 43
then may be manipulated so as to cause the grippers 39 and
21 40 to move toward one another as is shown in Figure 3. The
22 height of the gripper fingers 41 and 42 is somewhat less
23 that the distance between the pivot pins 9 and the outer
I surface of the pipe 1, thereby enabling the gripper fingers
41 and 42 to grip the chain in a position between the pins
a 9 and the outer surface of the pipe.
a The number of supports 30 fitted to the chain 6
I may vary, but a sufficient number should be applied and
a spaced circumferential of the loop L to provide adequate
I
lZ35~58
1 support for the second pipe section 2, and the spacing be-
2 tweet adjacent supports 30 should be such as to provide for
the application of adequate shifting and reforming forces
4 on the pipe section 2, as will be explained.
Following the application of the supports to the
chain 6, the jacks 56 may be fitted to the supports 30 via
7 the openings 52 and 53 and the respective bodies 57 adjusted
8 axially of the pipe 1 so that the jack screws 61 extend
9 beyond the free end 3 of the pipe 1. The end 4 of the
pipe 2 then may be moved into confronting relation with
11 the free end 3 of the pipe 1, following which the jack
12 screws 61 may be adjusted radially of the loop L to engage
13 the outer surface of the pipe 2 at circumferential spaced
14 points. The several jack screws, including the jack screw
24, may be manipulated to shift the pipe 2 transversely of
I the pupil to align the two pipe sections 1 and 2 axially.
17 Any tendency on the part of a jack body 57 to tilt is no-
18 sited by the engagement of the support 30 with the chain
19 6 and by the engagement of the leg 65 with the pipe 1.
After the pipe sections 1 and 2 have been aligned,
21 or substantially aligned, the individual jack screws 61 may
22 be adjusted to conform the configuration of the end 4 of
23 the pipe 2 to the end 3 of the pipe 1. If the number of
24 jacks is insufficient to enable proper reformation of the
pipe end 4, additional jacks may be applied to the chain 6
I at any desired location around the loop L so as to enable
27 forces to be applied to the pipe 2 as may be required to
I correct as much as possible any mismatch that may be present.
I Since any support 30 may be adjusted circumferential of the ¦
lZ351S8
1 loop L without necessitating slackening of the chain 6, and
2 since each jack body 57 is adjustable axially of the pipes
3 without necessitating slackening of the chain, the jack
4 screws may be adjusted 50 as to apply force at any selected
point on either of the pipes 1 and 2.
The clamp may be separated from the pipe 1 follow-
7 in the completion of welding operations by removal of some
8 or all of the jacks from the chain 6 or by release of the
latch 20 and removal of the free end of the chain from be-
tweet the plates 12.
11 The embodiment of the invention shown in Figure
12 5 corresponds to the previously described embodiment with
13 the exception that the operating means aye comprises a
14 toggle linkage. In the modified embodiment the toggle
linkage includes a mounting member 70 secured at one end to
lo the shaft 45 and pivoted at its other end to a threaded rod
17 71 on which a linearly adjustable actuator 72 is threaded.
18 The free end of the rod 71 may be accommodated in the slot
19 51 in the support leg 32 and the actuator 72 adjusted so
that it will bear against the leg I Manipulation of the
21 linkage in such manner as to expand it causes the legs 31
22 and 32 to rock about the fulcrum 38 and the grippers 39
23 and 40 to be clamped against opposite sides of the chain 6.
I The embodiment of the invention illustrated in
Figures 6-10 comprises a rim clamp 75 composed of a pair
I of arcuate segments 76 and 77 pivoted to one another at
a corresponding ends by a pivot pin 78. At the other end
I of the segment 76 is pivoted, as at 79, a latching paw
a 80 that is adapted to be engaged by an adjustable cam
lZ351~;~
l ¦ (not shown) forming part of a latch pin 81 and which may
2 ¦ be rocked out of engagement with the latch pin 81 by means
3 ¦ of a release arm 82 that is fixed to the pin and coupled to
4 ¦ an operating chain 83. The latching and release mechanism
5 ¦ is known.
¦ Adjacent the pivotal joined ends of the sex-
7 ¦ mints 76 and 77 each of the latter preferably has welded
8 ¦ thereto one or more radially inwardly extending projections
9 ¦ 84 which may engage the outer surface of the pipe section
10 ¦ l when the segments 76 and 77 encircle the pipe. This will
if ¦ provide an annular space 85 between the outer surface of
12 ¦ the pipe l and the inner surface of the clamp 75.
13 ¦ Each segment 76 and 77 also may be provided with
14 a number of threaded jack screws 86 which extend through
correspondingly threaded openings in the clamp segments
lo and which may be used to reform the free end of the pipe l.
17 The rim clamp 75 is adapted to accommodate a
18 plurality of supports 30 and jacks 56 like those referred
19 to earlier. In this case the supports 30 are mounted on
the ring segments by inserting the gripper fingers 41 and
21 42 in the annular space between the pipe surface and the
22 inner surface of the clamp, as is shown in Figure 9. The
23 operation of the supports 30 and jacks 56 in conjunction
I with the clamp 75 is the same as has been described earlier.
If it should be desired to provide the segments
I 76 and 77 of the ring clamp with laterally extending ribs
I or flanges 87, as is shown in Figures 9 and 10, then the
grippers of the support 30 may grip the segments radially
inwardly of the ribs, rather than occupy positions between
lZ3i~158
1 ¦ the clamp ring and the pipe surface.
2 ¦ The embodiment shown in Figures 11-13 comprises
¦ a rim clamp 88 similar to the clamp 75 in that it is come
4 ¦ posed of two arcuate segments 89 and 90 having at core-
5 ¦ sponging ends a latching paw 91 pivoted to the segment 90
a ¦ by a pivot pin 92. A release arm 93 pivoted to the segment
7 ¦ 89 as at 94 is operable to release the latch paw 91 when
8 ¦ the arm 93 is rotated in one direction by the application
9 ¦ of force on an operating chain 95.
10 ¦ The segments 89 and 90 are not simply pivoted to
11 ¦ one another at their other ends, as is the case with the
12 ¦ segments 76 and 77 of the clamp 75. Instead, the segments
13 ¦ 89 and 90 are coupled to one another by an over centering
14 latch mechanism 96 having a pair of links 97 joined at eon-
responding ends to a pivot 98 carried by the segment 89 and
I pivoted at their other ends to pins 99 that are fixed to
17 and project outwardly from a pair of links 100. The links
18 100 are pivoted to a pin 101 carried by the segment 90.
19 To one end of one of the links 100 is fixed one end of an
operating arm 102 which may be pivoted counterclockwise
21 about the pin 101 from the position shown in Figure 11 to
22 the position shown in Figure 12 so as to draw the confront-
23 in ends of the segments 89 and 90 toward one another.
I The clamp 88 includes a number of fixed, circus-
ferentially spaced, radially inwardly extending projections
I 103 icky the projections 84. If desired, the clamp 88 also
I may include threaded, reforming jack screws like the jack
screws 86 fitted to the clamp 75.
It will be understood that the clamp 88 may be
I
- 14
lZ35158
1 fitted with removable jack supports and jacks like those
2 described earlier. As is shown in Figure 13, the operating
arm 102 of the toggle mechanism 96 is spaced to one side of
4 the segments. The spacing is sufficient to enable a jack
screw 61 to extend between the segment 90 and the arm 102
when the clamp is clamped around the pipe section 1.
7 One advantage of the over centering latch mechanism
8 96 is that it enables the clamp 88 to be applied to and no-
9 moved from a pipe length more quickly than is the case with
the clamp 75. This is because the latch mechanism 96 may
11 be used to provide some slack or annular clearance between
12 the clamp 88 and the pipe section 1 so as to provide suffix
13 client working space for the latch paw 91 to seat upon and
14 be unseated from its latch pin and without having to make
any radial adjustment of the radially adjustable jack screws
I 86. As a.conse~uence, these jack screws need not be adjusted
17 once they have been set.
18 A further advantage of the latch mechanism 96
19 is that it enables all of the jack screws 86 to be dispensed
with, if desired, in favor of the more economical fixed
21 projections 103.
22 The disclosed embodiments are representative of
23 presently preferred forms of the invention, but are in-
a tended to be illustrative rather than definitive thereof.
The invention is defined in the claims.
I
a
